Embodiments of the present invention relate generally to energy storage systems and more particularly to a thermoelectric energy storage system and an associated method thereof.
Energy storage systems, such as electrical energy storage systems may use a charge cycle for storing energy and a discharge cycle for retrieval of the stored energy. In a thermoelectric energy storage system, during the charge cycle, a compressor is driven using electric power to compress a fluid and store the energy in a compressed fluid. Further, during the discharge cycle, the compressed fluid is expanded using a turbo expander to drive a generator for retrieval of the stored energy. However, such energy storage systems may require access to underground caverns for retaining pressure of the compressed fluid, which may not be economical and thus may be of limited deployment.
Further, certain other thermal energy storage systems may store solar energy in molten salt during the charge cycle. During discharge cycle, such thermal energy storage systems may retrieve the thermal energy by generating a vaporized working fluid from the molten salt, expand the vaporized working fluid, and generate electric energy. However, performance of thermodynamic cycles in the charge cycle and discharge cycle are limited by temperature constraints and available thermal sources. For example, during the discharge cycle, the heat exchange between working fluid and the thermal source are limited by a temperature difference between hot and cold sides of a heat exchanger. Typically, the difference in the temperature between the working fluid and the thermal source may be significant, and thereby reduce efficiency of the discharge cycle. Similarly, during a refrigeration-based charge cycle, the temperature of the working fluid in a condenser is limited by temperature of ambient air being used to cool the working fluid. Typically, a warmer ambient air may lead to generation of warmer working fluid from the condenser, and thereby reduce coefficient of performance of the charge cycle.
Thus, there is a need for an improved energy storage system and an associated method.